A Pilot Study to Evaluate Genipin in Staphylococcus aureus and Pseudomonas aeruginosa Keratitis Models: Modulation of Pro-Inflammatory Cytokines and Matrix Metalloproteinases.

Infectious keratitis is a vision-threatening microbial infection. The increasing antimicrobial resistance and the fact that severe cases often evolve into corneal perforation necessitate the development of alternative therapeutics for effective medical management. Genipin, a natural crosslinker, was recently shown to exert antimicrobial effects in an ex vivo model of microbial keratitis, highlighting its potential to serve as a novel treatment for infectious keratitis. This study aimed to evaluate the antimicrobial and anti-inflammatory effects of genipin in an in vivo model of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) keratitis. Clinical scores, confocal microscopy, plate count, and histology were carried out to evaluate the severity of keratitis. To assess the effect of genipin on inflammation, the gene expression of pro- and anti-inflammatory factors, including matrix metalloproteinases (MMPs), were evaluated. Genipin treatment alleviated the severity of bacterial keratitis by reducing bacterial load and repressing neutrophil infiltration. The expression of interleukin 1B (IL1B), interleukin 6 (IL6), interleukin 8 (IL8), interleukin 15 (IL15), tumor necrosis factor-α (TNF-α), and interferon γ (IFNγ), as well as MMP2 and MMP9, were significantly reduced in genipin-treated corneas. Genipin promoted corneal proteolysis and host resistance to S. aureus and P. aeruginosa infection by suppressing inflammatory cell infiltration, regulating inflammatory mediators, and downregulating the expression of MMP2 and MMP9.

Medical management and resolution of perinatal bilateral exophthalmia and secondary corneal ulcers in an Antillean manatee (Trichechus manatus manatus) neonate from Puerto Rico.

OBJECTIVE: To present a novel case of perinatal bilateral exophthalmos and corneal ulcers in a neonate Antillean manatee and describe the medical treatment that led to the resolution of the observed clinical signs and vision restoration. ANIMAL STUDIED: A manatee stranded alone in Puerto Rico on July 5, 2020. RESULTS: The manatee was found in critical condition with pronounced exophthalmos, lagophthalmos, and corneal opacification of both eyes (OU). Vision impairment was evident due to the lack of ocular menace reflex and bumping into the tank's walls. Biomicroscopy revealed conjunctival hyperemia and chemosis, limited third eyelid movement, but had viscous tears present OU. Dense, full-thickness, white to cream-colored cellular infiltrates affected 70% of the cornea with peripheral active vascularization OU. Rubeosis iridis was also present OU. Treatment consisted of supportive medical management, including nutritional support and topical treatment for ulcerative keratitis. Resolution of the corneal ulcers and functional vision were achieved after 6 weeks of therapy. Currently, bilateral, mild, intermittent exophthalmos is observed with no adverse clinical signs, and the calf is in good health. CONCLUSIONS: The extent of bilateral corneal disease on a neonatal calf may be a result of an intrauterine infection or possible trauma at or right after birth. While the latter may have led to exophthalmia and consequent corneal disease, the exact cause could not be determined. Supportive therapy and medical management of infectious keratitis were successful and led to vision recovery. This is the first report of ocular pathology in a neonatal manatee.

Queratitis por Mycobaterium abscessus: comunicación del primer caso en Paraguay / Keratitis due to Mycobaterium abscessus: first case report in Paraguay

Resumen Se presenta un caso clínico de queratitis por Mycobacterium abscessus en una mujer de 76 años, residente en la ciudad de Asunción, sin traumatismo ni cirugía ocular previa y con antecedente de una queratouveitis herpética. Por tratarse de una queratitis causada por un agente etiológico poco frecuente y por la importancia de un diagnóstico correcto y oportuno para la instauración del tratamiento adecuado, se comunica el primer caso de queratitis por micobacterias en Paraguay.

Abstract We present a clinical case of keratitis caused by M. abscessus in a 76-year-old female patient, resident in the city of Asunción, without trauma or previous ocular surgery and with a history of herpetic keratouveitis. Because it is a keratitis caused by a rare etiological agent and because of the importance of a correct and timely diagnosis for the establishment of appropriate treatment, the present case is reported, the first of Mycobacteria keratitis in Paraguay.

Minimum inhibitory concentrations and resistance for selected antimicrobial agents (including imipenem, linezolid and tigecycline) of bacteria obtained from eye infections.

Objective: To determine bacteria obtained from eye infections, both resistance and minimal inhibitory concentration (MIC) to gatifloxacin, moxifloxacin, tigecycline, linezolid and imipenem, in vitro. Methods: A cross-sectional descriptive study was undergone with 50 samples from 50 eyes of patients diagnosed with keratitis or endophthalmitis, who came to a consultation at the Fundación Oftalmológica de Santander (Floridablanca, Colombia) from August to November 2014. The MICs of the isolated microorganisms were established through Etest® strips (BioMérieux SA, Marcy-l'Etoile - France). Results: Of the 50 samples in total, 17 different bacteria species or groups were isolated. The main isolate for gram-positives was Methicillin Resistant Coagulase-Negative Staphylococcus (17 samples), and for gram-negatives was Pseudomonas aeruginosa (6 samples). The susceptibility percentages sorted from highest to lowest for gram-positive isolates (n=38) were: imipenem 90.3%, linezolid 87.9%, tigecycline 78.1%, gatifloxacin 68.8% and moxifloxacin 68.8%. For gram-negative isolates (n=12), they were: imipenem 72.7%, gatifloxacin 70%, moxifloxacin 66.7% (no reference cut-off points were found for Pseudomonas aeruginosa), tigecycline 22.2%, and linezolid 0% (as expected according to its inhibition spectrum). Conclusions: Although fourth generation fluoroquinolones are currently the preferred initial empirical monotherapy in our practice, given the increasing bacterial resistance, in cases in which gram-positive bacteria were isolated in the initial staining imipenem, linezolid or tigecycline could be used as an alternative. On the other hand, for cases of gram-negative bacteria, no antimicrobial susceptibility exceeded 80%, so using two antimicrobials looking for a synergy between them could be a better option. Abbreviations: S = Susceptibility, IS = Intermediate susceptibility, R = Resistance.

Infectious keratitis in southern Brazil: a comparison culture negative and culture positive patients / Ceratite infecciosa no sul do Brasil: comparação entre pacientes com cultura negativa e positiva

Abstract Purpose: To compare clinical-epidemiological profile and treatment outcome between culture negative and culture positive keratitis patients. Methods: Patients with suspected infectious keratitis seen at two ophthalmic hospitals in Curitiba, Brazil, between June 2014 and April 2016, were prospectively studied. Ophthalmological exam with corneal scraping and microbiological tests were performed. Data regarding follow up, surgical interventions and treatment outcome were collected after 12 weeks of the first visit trough medical chart review. From the results of the culture, two groups were formed: culture negative keratitis (CNK) and culture positive keratitis (CPK). Results: According to inclusion criteria 21 patients were classified as culture negative keratitis and 20 patients as culture positive keratitis. The number of patients on antibiotic drops at the first visit was greater in CNK group (90.5% versus 60%; p=0.032). Surgical procedures were necessary in 3 patients (15%) in CNK group and in 7 patients (36,8%) in CPK group (p=0.155). Treatment success was achieved by 85% (17/20) of the patients in CNK group and by 61% (11/18) of the patients in CPK group (p=0.144). There was no significant difference between groups regarding age, gender, place of residence, presence of comorbidities, risk factors for infectious keratitis, duration of symptoms and characteristics of corneal ulcer. Conclusions: Previous treatment with antibiotics correlates with negative culture results. There was no significant difference in treatment outcome between culture negative and culture positive keratitis patients.

Resumo Objetivo: Comparar os perfis clinico-epidemiológicos e os desfechos entre pacientes com ceratite com cultura positiva e pacientes com ceratite com cultura negativa. Métodos: Pacientes com ceratite infecciosa, atendidos em dois hospitais oftalmológicos em Curitiba, Brasil, entre junho de 2014 e abril de 2016, foram estudados prospectivamente. Exame oftalmológico, raspado de córnea e exames microbiológicos foram realizados no primeiro atendimento. Os dados quanto a seguimento e desfecho foram coletados após 12 semanas do primeiro atendimento através de revisão de prontuário. A partir dos resultados das culturas, dois grupos foram formados: ceratite com cultura negativa e ceratite com cultura positiva. Resultados: Vinte e um pacientes foram classificados como ceratite com cultura negativa e 20 como ceratite com cultura positiva. O número de pacientes em uso de colírio antibiótico no primeiro atendimento foi maior no grupo de cultura negativa (90,5% versus 60%; p=0,032). Sete pacientes (37%) no grupo cultura positiva precisaram de procedimentos cirúrgicos no manejo da ceratite, versus 3 pacientes (15%) do grupo cultura negativa (p=0,155). Oitenta e cinco por cento (17/20) dos pacientes do grupo cultura negativa alcançaram sucesso no tratamento, contra 61% (11/18) dos pacientes no grupo cultura positiva (p=0,144). Não houve diferença entre os grupos quanto a idade, gênero, local de procedência, presença de comorbidades, fatores de risco, duração dos sintomas e características da úlcera de córnea. Conclusão: Tratamento prévio com colírio de antibiótico correlaciona-se com resultados negativos de cultura. Não houve diferença no desfecho após tratamento entre os pacientes com cultura negativa e cultura positiva.

Contact lens-related polymicrobial keratitis: Acanthamoeba spp. genotype T4 and Candida albicans.

A 31-year-old female daily user of contact lenses sought medical attention, reporting blurred vision and irritation of the left eye. Slit-lamp examination revealed hyperemia and an irregular corneal epithelium surface, and empirical treatment was started. A corneal scrape was obtained and examined for the presence of fungi, bacteria, and Acanthamoeba spp. The results of the microbial culture revealed growth of Acanthamoeba spp. and Candida albicans. The Acanthamoeba isolate was characterized by cyst morphology as belonging to group II according to Pussard and Pons. Sequencing of the diagnostic fragment 3 (DF3) region located on the 18S ribosomal DNA identified the isolate as genotype T4. The patient was treated with chlorhexidine 0.02% and polyhexamethylene biguanide (PHMB) 0.02% drops for 5 months until the infection resolved. Lately, rare cases of polymicrobial keratitis associated with Acanthamoeba and Candida albicans have been reported. Cases of co-infection are more difficult to treat, since the specific treatment depends on precise identification of the agents involved.

Efeito terapêutico do crosslinking corneal na ceratite infecciosa / Therapeutic effect of corneal crosslinking on infectious keratitis

OBJETIVO: Avaliar o efeito do crosslinking (CXL) no tratamento de ceratite infecciosa, resistente ao tratamento clínico, e investigar a relação com o agente etiológico. MÉTODOS: Foram incluídos 11 pacientes com diagnóstico de ceratite infecciosa de etiologia bacteriana (sete olhos) e fúngica (quatro olhos) na Fundação Altino Ventura (FAV) no período de outubro de 2011 a maio de 2012. Os pacientes incluídos estavam em uso de colírios há pelo menos sete dias e não apresentavam melhora da infecção. Estes foram avaliados antes da realização do CXL e no período pós-operatório até cicatrização da úlcera. Para realização do CXL foram instiladas gotas de riboflavina a 0,1% e dextrano a 20%, a cada cinco minutos em um período de 30 minutos antes do procedimento, e durante a aplicação da luz ultravioleta A (UVA). A córnea foi exposta à UVA com comprimento de onda de 370ηm ± 5ηm e uma irradiância de 3mW/cm2. RESULTADOS: Os pacientes com infecção bacteriana obtiveram cura do processo infeccioso após o CXL e nenhum paciente com ceratite fúngica apresentou cicatrização. Observou-se associação significante (p = 0,003) entre o agente etiológico e a cicatrização. CONCLUSÃO: O CXL mostrou-se eficaz no tratamento da ceratite bacteriana resistente ao tratamento clínico, evitando a realização de transplante tectônico. Em relação à ceratite fúngica, este procedimento não influenciou na melhora do processo infeccioso.

PURPOSE: To evaluate the effect of corneal crosslinking (CXL) in the treatment of infectious keratitis resistant to medical treatment, and investigate the relation with the CXL outcome to the etiologic agent. METHODS: The study included 11 patients who were diagnosed with bacterial (seven eyes) or fungal keratitis (four eyes) at Altino Ventura Foundation from october 2011 to may 2012. All patients were using antibiotic eye drops for at least 7 days and have had no infection improvement. Patients were evaluated prior to CXL and the postoperative period until healing of the keratitis. For CXL, eyes were first instilled with a solution containing 0.1% riboflavin and 20% dextran for 30 min at a 5-minutes interval. Riboflavin-soaked eyes were then irradiated with UVA light (370ηm ± 5ηm) at 3mW/cm2 for 30 minutes. RESULTS: Eyes with bacterial infection exhibited improvement of infectious symptoms after CXL whereas eyes with fungal keratitis showed no improvement. Thus, there was a statistically significant correlation (p = 0.003) between the etiologic agent and the effectiveness of healing. CONCLUSION: CXL was effective in the treatment of bacterial keratitis resistant to clinical treatment, eliminating the need for surgery. However, CXL was not effective in managing fungal keratitis.

Características clínicas y epidemiológicas de la queratitis infecciosa en operados de queratoplastia penetrante óptica / Clinical and epidemiological characteristics of infectious keratitis in patients operated on by optic penetrating keratoplasty

Objetivo: describir las características clínicas y epidemiológicas de la queratitis infecciosa en la queratoplastia penetrante óptica. Métodos: se realizó una investigación observacional, descriptiva, longitudinal prospectiva, con una muestra de 31 pacientes con diagnóstico de queratitis infecciosa en el injerto corneal, después de una queratoplastia penetrante óptica. Atendidos en el Servicio de Córnea del Instituto Cubano de Oftalmología Ramón Pando Ferrer en fecha comprendida de marzo a noviembre del 2010. Las variables estudiadas fueron: edad, sexo, intervalo de tiempo entre la queratoplastia penetrante y el inicio de la infección, factores predisponentes asociados a la queratitis infecciosa, manifestaciones clínicas, complicaciones y estado final del injerto. Resultados: predominó el sexo masculino 61,3 por ciento y el grupo de edades de 30-44 años 45,2 por ciento. La mayoría de los casos presentaron una infección tardía, siendo el principal factor predisponente el uso de esteroides tópicos. El síntoma más frecuente fue la secreción 77,4 por ciento y el signo más significativo fue el edema corneal 74,1 por ciento. Predominó la localización periférica del infiltrado 51,6 por ciento, con un tamaño de 1-3 mm 48,4 por ciento y una profundidad hasta el tercio anterior 58,1 por ciento. La complicación más frecuente fue la hipertensión ocular secundaria con un 50 por ciento. El injerto mantuvo la transparencia solo en el 12,9 por ciento de los pacientes. Conclusiones: la queratitis microbiana después del trasplante de córnea es una complicación amenazante para la visión y puede llevar a la pérdida de la transparencia, debido a la formación de cicatriz corneal. Es necesario mantener el control de los factores predisponentes para disminuir la frecuencia de esta complicación

Objective: to describe the clinical and epidemiological characteristics of infectious keratitis in optic penetrating keratoplasty. Methods: prospective, longitudinal, descriptive and observational research of a sample of 31 patients diagnosed with infectious ketatitis in their corneal graft, after undergoing optic penetrating keratoplasty. They had been attended to in the Corneal Service of Ramon Pando Ferrer Cuban Institute of Ophthalmology from March to November 2010. The studied variables were age, sex, time lapse from the penetrating keratoplasty to the starting of infection, predisposing factors associated to infectious keratitis, clinical manifestations, complications and final condition of the graft. Results: males 61.3 percent and 30-44 y age group 45.2 percent were predominant. The majority of cases presented with late infection, being the use of topical steroids the main predisposing factor. The most frequent symptom was secretion 77.4 percent and the most significant sign was corneal edema 74.1 percent. Peripheral location of infiltrates 51.6 percent predominated, with size of 1-3 mm 48.4 percent percent.1 percent. The most common complication was secondary ocular hypertension 50 percent. The graft kept transparency just in 12.9 percent of patients. Conclusions: microbial keratitis after corneal transplantation is a threatening complication for the vision and may lead to loss of transparency due to formation of corneal scar. It is necessary to keep control over the predisposing factors to reduce the frequency of this complication

Bactericidal effect of S-nitrosothiols against clinical isolates from keratitis.

BACKGROUND: The purpose of this study was to evaluate the antimicrobial activity of two nitric oxide donors, ie, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylcysteine (SNAC), against clinical isolates from patients with infectious keratitis. METHODS: Reference broth microdilution assays were performed to determine the minimum inhibitory and bactericidal concentrations for GSNO and SNAC against four American Type Culture Collection strains and 52 clinical isolates from patients with infectious keratitis as follows: 14 (26.9%) Pseudomonas species; 13 (25.0%) coagulase-negative Staphylococci; 10 (19.2%) Staphylococcus aureus; nine (17.3%) Serratia marcescens; and six (11.5%) Enterobacter aerogenes. Sterility control and bacterial growth control were also performed. RESULTS: SNAC showed lower minimum inhibitory and bactericidal concentrations than GSNO for all clinical isolates from patients with infectious keratitis. For Gram-positive bacteria, mean minimum inhibitory and bactericidal concentrations were 2.1 ± 1.3 and 8.6 ± 3.8 mM for SNAC and 4.6 ± 3.2 and 21.5 ± 12.5 mM for GSNO (P < 0.01). For Gram-negative bacteria, mean minimum inhibitory and bactericidal concentrations were 3.3 ± 1.4 and 6.1 ± 3.4 mM for SNAC and 12.4 ± 5.4 and 26.5 ± 10.1 mM for GSNO (P < 0.01). The minimum bactericidal to inhibitory concentration ratio was ≤8 in 100% of all isolates tested for SNAC and in 94.2% tested for GSNO. CONCLUSIONS: SNAC and GSNO had effective inhibitory and bactericidal effects against bacterial isolates from keratitis. SNAC showed greater antimicrobial activity than GSNO against all bacteria. Gram-positive bacteria were more susceptible to the inhibitory and bactericidal effects of the S-nitrosothiols.

Queratitis infecciosa no viral: factores predisponentes, agentes etiológicos y diagnóstico de laboratorio / Non viral infectious keratitis: predisposing factors, etiologic agents and laboratory diagnosis

Las queratitis infecciosas poseen una elevada morbilidad, poniendo en riesgo la visión en casos graves. Dada la eficaz protección que brinda el epitelio corneal, para que ocurra una infección se requiere la presencia de factores condicionantes. El principal predisponente para las queratitis infecciosas es el uso de lentes de contacto, seguido por traumatismos y cirugías oculares y luego diversas afecciones locales o generales. Los agentes etiológicos abarcan una enorme diversidad de microorganismos, incluyendo bacterias, micobacterias, virus, hongos y parásitos. Para poder instaurar un tratamiento acotado se necesita un diagnóstico etiológico, lo que requiere una correcta toma de muestra y un exhaustivo análisis microbiológico.

Infectious keratitis cause significant morbidity and, if it is not promptly and appropriately treated, can lead to severe ocular disability. Almost all cases of keratitis are associated to predisposing conditions. In occident, the main risk factor is contact lens wear, but previous ocular surgery or trauma are also important, as well as various ocular surface diseases. An enormous diversity of etiologic agents for infectious keratitis exist, including virus, bacteria, mycobacteria, fungi and parasites. This review provides literature and personal based information about main predisposing factors, etiologic agents and pathophysiology of infectious keratitis, excluding those of viral origin. Focus is made on microbiologic procedures, describing stains and media that should be used, and highlighting their utility. A special mention on particular situations is made, including laboratory diagnosis of Acanthamoeba keratitis, utility of lens cases analysis, keratitis in patients with previous treatment, as well as molecular biology techniques described in ophthalmology.